Serial Fan Device

ABSTRACT

a serial fan device including two fans linked serially is provided. Each of the two fans has a housing, a driving member and a fan wheel, the housing has an outer frame and a base, the outer frame has two openings and a guiding channel linking the two openings, the driving member is disposed on the base, and the fan wheel is rotatably coupled with the driving member. At least one of the two fans has a positioning rim on the outer frame for the base to couple therewith, and a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim. Accordingly, the radial buffer gap can largely reduce the vibration transmitted from the base to the outer frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a serial fan device and, more particularly, it relates to a serial fan device formed by a plurality of fans serially combined.

2. Description of the Related Art

A conventional serial fan device is usually formed by a plurality of series-connected fans so as to provide improved wind volume and enhanced cooling effect relative to a single fan. Unfortunately, since there is vibration in the operation of a fan usually, the degree of the vibration of a serial fan device formed by plural fans can be much more serious than that of a single fan. When the serial fan device is applied in an electronic system, such as a computer server, this kind of serious vibration not only induces noises, but also lowers the operational stability of the electronic system as well as accelerates the deterioration of the circuit joints inside the electronic system, and thus shortens the lifetime of this electronic system.

Therefore, referring to FIG. 1, an invention entitled as “Vibration Damping Structure of Serial Fan Device,” with a Taiwan patent number of 1324504, is provided to disclose a conventional serial fan device 9 capable of vibration damping. This serial fan device 9 includes two frames 91, 92 connecting with each other in series, with each of the frames 91, 92 having a base 911 or 921 adapted to couple with an impeller. Specifically, there is a damping member 93 inserted in a space between opposite faces of the series-connected frames 91, 92. Accordingly, since the damping member 93 is formed by flexible material for vibration damping and buffering, the damping member 93 is able to damp the vibration from the impellers inside the frames 91, 92 to restrain resonance and noise of the frames 91, 92 when the impellers turn.

However, although the damping member 93 can restrain resonance and noise of the frames 91, 92, the operational vibration can still transmit via routes from the bases 911, 921 to the other parts of the frames 91, 92 since the impellers are rotatably mounted on the bases 911, 921. As a result, the damping performance provided by the damping member 93 against the resonance and noise is quite limited, and thus the remaining vibration can still lower the operational stability of an electronic system, induce noises, and shorten the lifetime of this electronic system when the serial fan device 9 is installed in this electronic system and operated. Moreover, the said remaining vibration may also cause a fault or failure in reading operation of a hard disk in the electronic system.

As a result, it is necessary to improve the conventional serial fan device.

SUMMARY OF THE INVENTION

It is therefore the objective of this invention to provide a serial fan device to efficiently break a route for vibration transmission, to largely damp the vibration caused by operation of a fan wheel, and to maintain operational stability and lower noise of an electronic system.

One embodiment of the invention discloses a serial fan device, which includes two fans linked serially. Each of the two fans has a housing, a driving member and a fan wheel, the housing has an outer frame and a base, the outer frame has two openings and a guiding channel linking the two openings, the driving member is disposed on the base, and the fan wheel is rotatably coupled with the driving member. At least one of the two fans has a positioning rim on the outer frame for the base to couple therewith, the positioning rim of the outer frame has a minimal inner diameter, and the base has a maximal outer diameter smaller than or equal to the minimal inner diameter. Preferably, the positioning rim has an axial shoulder abutting against the base. More preferably, a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim.

In a preferred form shown, the outer frame of the fan having the radial buffer gap is a hollow body, the positioning rim is formed on an end section of the guiding channel defining one of the two openings, the base of the housing includes a seat, a plurality of connecters and a coupling member, the plurality of connecters connects with the seat by one end and the coupling member by another end, the base couples with the positioning rim by the coupling member, the coupling member abuts against the axial shoulder, and an outer periphery of the coupling member is spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the outer frame of the fan having the radial buffer gap has a hollow body, a plurality of connecters and a coupling member, the plurality of connecters connects with an inner periphery of the hollow body by one end and the coupling member by another end, the base is a seat, the positioning rim is formed on an end of the coupling member, the axial shoulder is arranged on the inner periphery of the positioning rim, the base couples with the positioning rim and abuts against the axial shoulder, and the outer periphery of the base is spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the outer frame of the fan having the radial buffer gap is a hollow body, the positioning rim is formed on an end section of the guiding channel defining one of the two openings, the base of the housing includes a seat and a plurality of connecters, the plurality of connecters connects with the seat by one end and the positioning rim by another end, each end of the connecters connecting with the positioning rim has an axial edge abutting against the axial shoulder and an radial edge spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the two fans are a first fan and a second fan, the base of the first fan is spaced from the inner periphery of the positioning rim of the first fan by the radial buffer gap, and the base of the second fan is spaced from the inner periphery of the positioning rim of the second fan by the radial buffer gap.

In the preferred form shown, the bases of the first and second fans are axially clamped by and between the axial shoulders of the first and second fans.

In the preferred form shown, the first and second fans are coupled with each other by a fixing assembly. Preferably, the fixing assembly includes a first hook member arranged on the first fan and a second hook member arranged on the second fan, and the first and second hook members are capable of detachably engaging with each other.

In a preferred form shown, a damping member is inserted between the two fans.

In the preferred form shown, each of the bases of the first and second fans has a recess for the damping member to be received in a space jointly formed by the recesses and between the bases of the first fan and the second fan.

In the preferred form shown, the damping member includes an annular flange on a periphery thereof, and the annular flange is clamped by lateral walls of the seats of the two fans.

In a preferred form shown, an edge of one of the two openings has an engaging notch, the said opening having the engaging notch has the positioning rim for the base to couple therewith, and the base has an engaging protrusion corresponding to and able to insert into the engaging notch.

In the preferred form shown, lateral walls of the engaging notch form two opposite limiting flanges respectively, two guiding flanges are formed on two opposite lateral walls of the engaging protrusion, and the engaging protrusion rests inside the engaging notch with the two limiting flanges engaging with the two guiding flanges respectively.

In a preferred form shown, the positioning rim of the outer frame has a connecting groove and the base has an elastic hook corresponding to and able to insert into the connecting groove.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is an exploded and perspective view of a conventional serial fan device.

FIG. 2 is an exploded and perspective view of a serial fan device according to a first embodiment of the invention.

FIG. 3 is a cross-sectional view of the serial fan device according to the first embodiment.

FIG. 4 is a partially enlarged cross-sectional view of the serial fan device according to the first embodiment.

FIG. 5 is an exploded and perspective view of the serial fan device according to the first embodiment with engaging notches and engaging protrusions.

FIG. 6 is a partially enlarged and perspective view of one pair of the engaging notches and engaging protrusions of the serial fan device according to the first embodiment.

FIG. 7 is a partially enlarged and perspective view of one pair of the engaging notches and engaging protrusions of the serial fan device according to the first embodiment with limiting flanges and guiding flanges.

FIG. 8 is a cross-sectional view of the serial fan device according to the first embodiment with a space formed by recesses for receiving a damping member.

FIG. 9 is a cross-sectional view of the serial fan device according to the first embodiment with two separate recesses and a damping member clamped by bottom walls of the recesses.

FIG. 10 is a cross-sectional view of the serial fan device according to the first embodiment with a damping member having an annular flange on a periphery thereof.

FIG. 11 is a cross-sectional view of a serial fan device according to a second embodiment of the invention.

FIG. 12 is a partially enlarged and cross-sectional view of the serial fan device according to the second embodiment.

FIG. 13 is an exploded and perspective view of the serial fan device according to the second embodiment with connecting grooves and elastic hooks.

FIG. 14 is a detailed and perspective view of one pair of the connecting grooves and elastic hooks of the serial fan device according to the second embodiment.

FIG. 15 is a detailed and cross-sectional view of one pair of the connecting grooves and elastic hooks of the serial fan device according to the second embodiment.

FIG. 16 is an exploded and perspective view of a serial fan device according to a third embodiment of the invention.

FIG. 17 is a cross-sectional view of the serial fan device according to the third embodiment.

FIG. 18 is a detailed cross-sectional view of the serial fan device according to the third embodiment.

FIG. 19 is a cross-sectional view of the serial fan device according to the first embodiment wherein only one of two fans has a radial buffer gap.

In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first,” “second,” “third,” “bottom,” “inner,” “outer” and similar terms are used hereinafter, it should be understood that these terms refer only to the structure shown in the drawings as it would appear to a person viewing the drawings, and are utilized only to facilitate describing the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2 and 3, a first embodiment of a serial fan device of the present invention is shown, which includes a first fan F1 and a second fan F2, wherein axial directions of the first and second fans F1, F2 are in alignment and these two fans F1, F2 are linked serially.

The first fan F1 includes a housing 1, a driving member 2 and a fan wheel 3. The housing 1 includes an outer frame 11 and a base 12. The outer frame 11 has two openings 111, 112 and a guiding channel 113 linking these two openings 111, 112, wherein any one of the openings 111, 112 serves as an air inlet and the other one serves as an air outlet, such as the opening 111 serves as the air inlet while the opening 112 serves as the air outlet, and vice versa. The outer frame 11 has a positioning rim 114 with an axial shoulder 115 forming a supporting surface facing the opening 112. Therefore, the base 12 can be inserted in and surrounded by the positioning rim 114 and abut against the supporting surface of the axial shoulder 115.

Please refer to FIG. 3 and further to FIG. 4. The positioning rim 114 of the outer frame 11 has an inner periphery with a minimal inner diameter “d1.” The base 12 has an outer periphery with a maximal outer diameter “d2” not larger than, namely being smaller than or equal to, the minimal inner diameter “d1,” so as to form a radial buffer gap “D” between the outer periphery of the base 12 and the inner periphery of the positioning rim 114. The radial buffer gap “D” can totally or partially separate the said inner and outer peripheries. Moreover, the driving member 2 is disposed on the base 12 of the housing 1, and the fan wheel 3 is rotatably coupled with the driving member 2. With the rotation of the fan wheel 3, an air current can be induced and pass through the guiding channel 113 by entering via one of the openings 111, 112 and existing via the other one of them, such as sequentially flowing through the opening 111, guiding channel 113 and opening 112. The driving member 2 may include elements for turning the fan wheel 3, such as silicon steel plates, stator coils and a control circuit board.

In this first embodiment, the outer frame 11 of the housing 1 is a hollow body 11 a, the positioning rim 114 is formed on an end section of the guiding channel 113 defining the opening 112, and the axial shoulder 115 is arranged on the inner periphery of the positioning rim 114. The base 12 of the housing 1 includes a seat 12 a, a plurality of connecters 12 b and a coupling member 12 c. The plurality of connecters 12 b locates between the seat 12 a and the coupling member 12 c while connecting with the seat 12 a by one end and the coupling member 12 c by another end. Each of the connecters 12 b is in the shape of a rib and, preferably, is a blade-shaped rib. The coupling member 12 c is in the shape of a ring around the seat 12 a and the plural connecters 12 b. Thereby, as shown in FIGS. 3 and 4, the base 12 couples with the positioning rim 114 by the coupling member 12 c, with the coupling member 12 c abutting against the supporting surface of the axial shoulder 115, and with an outer periphery of the coupling member 12 c being spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

Referring to FIGS. 5 and 6 now, it is preferable that an edge of the opening 112 of the outer frame 11 has at least one engaging notch 116 and the base 12 has at least one engaging protrusion 122 corresponding to and able to insert into the said at least one engaging notch 116. Therefore, with the engagement of the engaging notch 116 and the protrusion 122, the outer frame 11 can be easily coupled with the base 12 in a predetermined orientation, and any undesirable relative rotation between the outer frame 11 and base 12 is also avoided as well as a preferred performance of engagement therebetween is provided. Besides, as shown by FIG. 7, lateral walls of the engaging notch 116 preferably form two opposite limiting flanges 117 while two guiding flanges 122 a are formed on two opposite lateral walls of the engaging protrusion 122. As a result, the guiding flanges 122 a guide the engaging protrusion 122 to pass through an opening between the limiting flanges 117 and to rest inside the engaging notch 116 while the engaging portion 122 is pressed toward the engaging notch 116 by an external force. Finally, the two limiting flanges 117 engage with the two guiding flanges 122 a respectively to prevent the base 12 from an axial reverse movement leading to disengagement of the base 12 relative to the outer frame 11.

Regarding to the second fan F2, the structure of the second fan F2 is basically similar to that of the first fan F1; namely, the second fan F2 also includes a housing 1, a driving member 2 and a fan wheel 3 identical to those described above. When the first and second fans F1, F2 link with each other serially, the bases 12 of these two fans F1, F2 abut against each other and are axially clamped by and between the axial shoulders 115 of these two fans F1, F2 while the radial buffer gaps “D” are still remained. Furthermore, in order to link the first and second fans F1, F2 and to keep their relative positions, it is preferred to further include a fixing assembly 4 for firmly coupling these two fans F1, F2 by hooking, screwing or welding. In this embodiment, the fixing assembly 4 includes a first hook member 41 arranged on the first fan F1 and a second hook member 42 arranged on the second fan F2, and the first and second hook members 41, 42 are capable of detachably engaging with each other, so that the fixing assembly 4 can prevent any one of the fans F1, F2 from disengagement and rotation relative to the other one thereof.

Referring to FIG. 8, it is preferable that a damping member 5 is inserted between the first and second fans F1, F2. The damping member 5 can be formed by a material able to provide functions of damping and buffering, such as rubber, foam, sponge, polyurethane, etc. As shown in FIG. 8, each of the bases 12 of the first and second fans F1, F2 has a recess 121 and the recess 121 of the first fan F1 communicates with the recess 121 of the second fan F2 for the damping member 5 to be received in the space jointly formed by the two recesses 121 and sandwiched between the bases 12 of the first fan F1 and the second fan F2. Alternatively, as shown in FIG. 9, the recesses 121 of the first and second fans F1, F2 can be separated while the damping member 5 is clamped by bottom walls of the recesses 121. With this damping member 5, the vibration caused by rotation of the fan wheels 3 can be damped by the damping member 5 when the fan wheels 3 of the first and second fans F1, F2 are operated. Moreover, referring to FIG. 10, the damping member 5 received in the recesses 121 shown in the FIG. 8 can be modified to further include an annular flange 51 on a periphery of the damping member 5, so that the damping member 5 can totally separate the seats 12 a of the first and second fans F1, F2 and firmly engaged therebetween, with the annular flange 51 being clamped between lateral walls of the seats 12 a of the two fans F1, F2.

Referring to FIGS. 11 and 12, a second embodiment of the serial fan device of the present invention is shown, which also includes a first fan F1 and a second fan F2. The first and second fans F1, F2 of this embodiment are similar to those of the first embodiment except for the following structural difference. In this second embodiment, the outer frame 11 of the housing 1 includes a hollow body 11 a, a plurality of connecters 11 b and a coupling member 11 c. The plurality of connecters 11 b locates between the hollow body 11 a and the coupling member 11 c while connecting with an inner periphery of the hollow body 11 a by one end and the coupling member 11 c by another end. Each of the connecters 11 b is in the shape of a rib and, preferably, is a blade-shaped rib. The coupling member 11 c is in the shape of a ring received in the hollow body 11 a. The base 12 is a seat 12 a, the positioning rim 114 is formed on an end of the coupling member 11 c, and an axial shoulder 115 is arranged on the inner periphery of the positioning rim 114. Thereby, the base 12, the seat 12 a namely, couples with the positioning rim 114 and abuts against a supporting surface of the axial shoulder 115, and an outer periphery of the base 12 is spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

Additionally, as shown in FIGS. 13-15, it is preferable that the positioning rim 114 of the outer frame 11 has at least one connecting groove 118 and the base 12 has at least one elastic hook 123 corresponding to and able to insert into the said at least one connecting groove 118. Therefore, the base 12 with the elastic hook 123 can be easily coupled with the outer frame 11 with the connecting groove 118, and thus functions of convenient assembly and anti-disengagement are accordingly provided.

Referring to FIGS. 16-18, a third embodiment of the serial fan device of the present invention is shown, which also includes a first fan F1 and a second fan F2. The first and second fans F1, F2 of this embodiment are similar to those of the first embodiment except that the coupling member 12 c of the base 12 in the first embodiment is omitted. As a result, the plurality of connecters 12 b connects with the seat 12 a by one end and the positioning rim 114 by another end. As shown by FIG. 18, each end of the connecters 12 b connecting with the positioning rim 114 has an axial edge 121 b abutting against the axial shoulder 115 and a radial edge 122 b spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

Additionally, although all the embodiments show that, for each of the first and second fans F1, F2, the maximal outer diameter “d2” of the base 12 is not larger than the minimal inner diameter “d1” of the positioning rim 114, the above described relationship of the maximal outer diameter “d2” and the minimal inner diameter “d1” can only be applied to one of the two fans F1, F2 as shown in FIG. 19.

In sum, with the above illustrated embodiments of the serial fan device, since the positions of the bases 12 of the first and second fans F1, F2 are axially fixed and at least one of the fans F1, F2 has its base 12 with a maximal outer diameter “d2” not larger than a minimal inner diameter “d1” of its positioning rim 114, the vibration caused by the operation of the fan wheel 3 and transmitted to the base 12 through the driving member 2 can be efficiently isolated from the outer frame 11 of the housing 1 by the radial buffer gap “D.” Consequently, the operational stability of an electronic system with this serial fan device can be maintained as well as a low noise performance is acquired. Besides, even if the bases 12 are axially clamped and fixed, an efficient damping and buffering effect is still achievable for noise-reducing and lifetime prolonging as long as the damping member 5 is inserted between the first and second fans F1, F2 to damp the vibration induced by the rotation of the fan wheel 3.

Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims. 

What is claimed is:
 1. A serial fan device comprising: two fans linked serially, wherein each of the two fans has a housing, a driving member and a fan wheel, wherein the housing has an outer frame and a base, wherein the outer frame has two openings and a guiding channel linking the two openings, wherein the driving member is disposed on the base, and wherein the fan wheel is rotatably coupled with the driving member, wherein at least one of the two fans has a positioning rim on the outer frame for the base to couple therewith, wherein the positioning rim of the outer frame has a minimal inner diameter, and wherein the base has a maximal outer diameter smaller than or equal to the minimal inner diameter.
 2. The serial fan device as claimed in claim 1, wherein a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim.
 3. The serial fan device as claimed in claim 2, wherein the positioning rim has an axial shoulder abutting against the base.
 4. The serial fan device as claimed in claim 3, wherein the outer frame of the fan having the radial buffer gap is a hollow body, wherein the positioning rim is formed on an end section of the guiding channel defining one of the two openings, wherein the base of the housing includes a seat, a plurality of connecters and a coupling member, wherein the plurality of connecters connects with the seat by one end and the coupling member by another end, wherein the base couples with the positioning rim by the coupling member, wherein the coupling member abuts against the axial shoulder, and wherein an outer periphery of the coupling member is spaced from the inner periphery of the positioning rim by the radial buffer gap.
 5. The serial fan device as claimed in claim 3, wherein the outer frame of the fan having the radial buffer gap has a hollow body, a plurality of connecters and a coupling member, wherein the plurality of connecters connects with an inner periphery of the hollow body by one end and the coupling member by another end, wherein the base is a seat, wherein the positioning rim is formed on an end of the coupling member, wherein the axial shoulder is arranged on the inner periphery of the positioning rim, wherein the base couples with the positioning rim and abuts against the axial shoulder, and wherein the outer periphery of the base is spaced from the inner periphery of the positioning rim by the radial buffer gap.
 6. The serial fan device as claimed in claim 3, wherein the outer frame of the fan having the radial buffer gap is a hollow body, wherein the positioning rim is formed on an end section of the guiding channel defining one of the two openings, wherein the base of the housing includes a seat and a plurality of connecters, wherein the plurality of connecters connects with the seat by one end and the positioning rim by another end, wherein each end of the connecters connecting with the positioning rim has an axial edge abutting against the axial shoulder and a radial edge spaced from the inner periphery of the positioning rim by the radial buffer gap.
 7. The serial fan device as claimed in claim 3, wherein the two fans are a first fan and a second fan, wherein the base of the first fan is spaced from the inner periphery of the positioning rim of the first fan by the radial buffer gap, and wherein the base of the second fan is spaced from the inner periphery of the positioning rim of the second fan by the radial buffer gap.
 8. The serial fan device as claimed in claim 7, wherein the bases of the first and second fans are axially clamped by and between the axial shoulders of the first and second fans.
 9. The serial fan device n as claimed in claim 7, wherein the first and second fans are coupled with each other by a fixing assembly.
 10. The serial fan device as claimed in claim 9, wherein the fixing assembly includes a first hook member arranged on the first fan and a second hook member arranged on the second fan, and wherein the first and second hook members are capable of detachably engaging with each other.
 11. The serial fan device as claimed in claim 1, further comprising a damping member inserted between the two fans.
 12. The serial fan device as claimed in claim 7, further comprising a damping member inserted between the first and second fans.
 13. The serial fan device as claimed in claim 12, wherein each of the bases of the first and second fans has a recess for the damping member to be received in a space jointly formed by the recesses and between the bases of the first fan and the second fan.
 14. The serial fan device as claimed in claim 12, wherein the damping member includes an annular flange on a periphery thereof, and the annular flange is clamped by lateral walls of the seats of the two fans.
 15. The serial fan device as claimed in claim 1, wherein an edge of one of the two openings has an engaging notch, the said opening having the engaging notch has the positioning rim for the base to couple therewith, and the base has an engaging protrusion corresponding to and able to insert into the engaging notch.
 16. The serial fan device as claimed in claim 15, wherein lateral walls of the engaging notch form two opposite limiting flanges respectively, wherein two guiding flanges are formed on two opposite lateral walls of the engaging protrusion, and the engaging protrusion rests inside the engaging notch, and with the two limiting flanges engaging with the two guiding flanges respectively.
 17. The serial fan device as claimed in claim 1, wherein the positioning rim of the outer frame has a connecting groove, and the base has an elastic hook corresponding to and able to insert into the connecting groove.
 18. The serial fan device as claimed in claim 4, wherein the coupling member is a ring.
 19. The serial fan device as claimed in claim 5, wherein the coupling member is a ring. 